Automatic analyzing apparatus

ABSTRACT

An automatic analyzing apparatus for effecting chemical analyses for various sample liquids such as blood, urine, and the like, comprising a sample delivery pump for metering a sample liquid into a reaction cuvette, a reagent delivery pump for delivering to the reaction cuvette a given amount of a given reagent selected from a plurality of reagents contained in a reagent cassette, to form a test liquid, a feed mechanism for successively supplying reaction cuvettes along a circular reaction line, a plurality of photometering sections arranged along the reaction line for effecting a plurality of photometric and/or nephelometric and/or fluorometric measurements for each test liquid at different time instances to produce a plurality of photometric results, and circuitry for receiving the photometric results and selecting therefrom given quantitative analytical data of a given test item.

This is a division of application Ser. No. 139,469 filed Apr. 11, 1980,abandoned.

BACKGROUND OF THE INVENTION

This invention relates to an automatic analyzing apparatus forautomatically effecting chemical analyses for various sample fluids suchas (but not limited to): cerebrospinal fluid, blood, urine, and thelike.

Automatic chemistry analyzers can be roughly divided into two broadcategories: continuous flow or discrete systems. Presently the majorityof analyzer models employ the discrete approach to automation.

In a discrete system, each test is carried through the analyticalprocess in its own dedicated (discrete) container or compartment.Current discrete analyzers can be further classified into two majorsub-categories; sequential and centrifugal analyzers.

In sequential testers, all tests are performed sequentially, one afteranother, so that at any given point in time all tests in process are ina somewhat different stage of progress. In general, sample and reagentare metered into a vessel which is fed along a given path and the testliquids in each of the vessels are treated to each aspect of theanalysis (reagent addition, mixing, quantitating, etc.) in sequence.

Centrifugal analyzers are also discrete but test liquids are processedin parallel to one another. All samples in process are in the same stageof analysis at the same time. In operation, samples and reagent arepre-measured and pre-loaded into appropriate compartments arranged aboutthe circumference of a rotor disc, whereupon it is placed on acentrifuge and rotated at a high speed past a photometer device.Centrifugal force mixes all samples with reagent at the same time andhence each of the test liquids is in the same stage of analysis at anygiven point in time.

The majority of analyzers, regardless of the above mentioned categories,are capable of performing more than one type of test item. There arethree broad categories of methods for providing for multi-testcapability.

What shall hereinafter be referred to as Random Access Testers currentlyrequire individual test packs which are pre-packaged with theappropriate reagents required to perform one test of a given test type.These test packs are loaded into the instrument system according to theanalyst's needs, charged with a sample liquid, and processed in adiscrete manner. Random access testers offer great convenience andflexibility but currently available embodiments have low productivitieswhen compared with other means of providing multi-test item capability.In addition, the requirement for pre-packaged test packs makes operatingcosts much higher than the alternate methods.

Another means of performing a plurality of tests on each of a pluralityof samples is sequentially by test-item batch. All samples are analyzedsequentially or centrifugally for a given test item. When all sampleshave been analyzed for a given test item, the system is changed over, orsomehow modified, to perform a different test item and all appropriatesamples are re-treated. When all samples have been processed for therequired test items, the results of each samples' test items must becollated to allow including all of a given samples analytical results ona single report form for return to a physician, etc. Such systems areusually referred to as `single channel` systems. Single channel systemsare usually considered most appropriate for treating a batch orplurality of samples, as the effort required to change-over from onetest item to another is generally neither convenient nor cost-effectiveto treat one sample for a plurality of test items. Additionally, at anygiven moment in time, only one test item is avaliable for immediate use.

Simultaneous analyzers have a plurality of analytical channels whichenable a plurality of test items to be performed simultaneously on eachsample. Such systems are commonly referred to as `multi channel`analyzers. Multi-channel analyzers do make more than one test itemavailable at any given point in time, do eliminate the data collatingtask required of single channel analyzers and in general, do have higherproductivities than single-channel analyzers by virtue of the fact thatthey are constructed as a plurality of single-channel analyzers combinedinto one device. This last feature is a drawback in that it makes theanalyzer system complicated in construction, large in size, andgenerally, much higher in cost than single-channel discrete, continuousflow or centrifugal analyzers.

In the known analytical systems of the non-centrifugal type, photometricquantitation is carried out after some time period from the initiationof the test reaction, i.e. when the test liquid has traveled along theprocessing line by some given fixed distance. Therefore, the reactiontime is fixed as a function of the length or circumference of theprocessing line, which may or may not be optimal with respect to a giventest item and/or sample.

Additionally, sequntial testers have only one photometer position perchannel, severely limiting the amount of photometric data which can bemade available. No photometric data can be made avilable until a testliquid reaches the photometer station, typically, 8-10 (often 30)minutes from the time of mixing of sample with reagent. Once a testliquid reaches a photometer station, the amount of time which is devotedto photometric measurement essentially limits the speed of analysis of agiven sequential tester, i.e. if 60 seconds is devoted to photometricquantitation, then the processing rate is limited to 60 tests per hour.This feature forces a trade-off between processing rate and photometricquantitation time especially for `kinetic` test (ex. enzyme rate tests)which require photometric measurement over long periods of time in orderto provide for best accuracy and precision of analysis.

SUMMARY OF THE INVENTION

The present invention has as its object to provide for an automaticanalyzing apparatus which is so constructed that the above drawbacks canbe avoided while insuring consistently reliable results.

According to the invention, an apparatus for effecting automaticanalysis comprises means for successively feeding reaction vessels, eachcontaining a respective test liquid to be analyzed, along a givenreaction line;

means for delivering (a) given amount(s) of (a) given reagent(s),corresponding to a test item to be measured, into a reaction vessel onthe reaction line to form a test liquid;

a plurality of photometering means arranged at different measuringpositions distributed along the reaction line for effecting a pluralityof photometric measurements for a respective test liquid in a vessel atdifferent time instances;

means for receving results of said plurality of photometric measurementsand selecting therefrom given quantitative analytical data of a giventest item for the test liquid in a reaction vessel; and

means for discharging the test liquid out of the reaction vessel afterthe quantitative analysis for the given test item has been performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a principal construction of anautomatic analyzing apparatus according to the invention;

FIG. 2 is a graph showing typical reaction state of a test liquid;

FIGS. 3 and 4 are perspective views illustrating an embodiment of theautomatic analyzing apparatus of the invention;

FIG. 5 is a schematic plan view showing an arrangement of variousportions of the apparatus shown in FIGS. 3 and 4;

FIG. 6 is a plan view showing a photometering section of the apparatusof FIG. 5;

FIG. 7 is a schematic cross-sectional view showing the photometeringsection;

FIG. 8 is a plan view showing a rotary filter unit illustrated in FIGS.6 and 7;

FIGS. 9A and 9B are graphs showing reaction curves;

FIG. 10 is a chart for explaining an operation of the apparatusaccording to the invention;

FIG. 11 is a perspective view showing an embodiment of a cuvette for usein the apparatus according to the invention;

FIGS. 12A and 12B are side views illustrating a manner of holding thecuvette of FIG. 11;

FIG. 13 is a plan view showing an embodiment of a reagent cassette;

FIG. 14 is a perspective view illustrating the reagent cassette;

FIG. 15 is a block diagram showing a manner of controlling a reagentfeed mechanism for minimizing a total travelling distance of the reagentcassette;

FIG. 16 is a schematic view illustrating an embodiment of the cassetteholder comprising separate refrigerator and room temperature portion;

FIG. 17 is a perspective view showing an embodiment of the refrigeratorof FIG. 16;

FIG. 18 is a schematic view explaining a delivery operation of thereagent delivery mechanism shown in FIG. 5;

FIG. 19 is a schematic view showing an embodiment of the reagentdelivery mechanism;

FIGS. 20A and 20B are a perspective view and a graph, respectively,showing an embodiment of a liquid level detector of the reagent deliverymechanism and a relation between an amount of sucked liquid and adetection output, respectively;

FIGS. 21A and 21B are a cross-sectional view and a graph showing anotherembodiment of the liquid level detector;

FIGS. 22A and 22B show still another embodiment of the liquid leveldetector;

FIG. 23 is a perspective view illustrating an embodiment of a liquidlevel detector for a reagent in a reagent bottle;

FIG. 24 is a perspective view showing another embodiment of the reagentlevel detector;

FIG. 25 is a schematic view showing an embodiment of a probe washingdevice;

FIG. 26 is a perspective view depicting another embodiment of thewashing device;

FIGS. 27A and 27B are schematic views for explaining the operation ofthe washing device shown in FIG. 26;

FIG. 28 is a block diagram showing a manner of connecting the automaticanalyzing apparatus according to the invention to a computer installedat a hospital;

FIG. 29 is a block diagram illustrating a manner of coupling theapparatus according to the invention with a back-up computer through acommunication line;

FIG. 30 is a block diagram showing a manner of controlling or operatinga plurality of the analyzing apparatuses according to the invention bymeans of a single controlling unit;

FIG. 31 is a flow chart showing an embodiment of a patient data systemusing the apparatus according to the invention;

FIG. 32 is a flow chart showing another embodiment of the patient datasystem;

FIG. 33 is a plan view showing a format of a patient card for use in thepatient data system;

FIG. 34 is a schematic view showing an embodiment of a cuvette andliquid discharging mechanism;

FIG. 35 is a schematic view showing another embodiment of thedischarging device;

FIG. 36 is a schematic view showing still another embodiment of thedischarging device;

FIG. 37 is a schematic view showing another embodiment of the apparatusaccording to the invention;

FIG. 38 is a schematic view showing an embodiment of an ionconcentration measuring device which may be installed in the apparatusaccording to the invention;

FIG. 39 is a schematic view showing another embodiment of the ionconcentration measuring device;

FIG. 40 is a block diagram showing an embodiment of a signal processingcircuit of the ion concentration measuring devices shown in FIGS. 38 and39;

FIG. 41 is a cross section showing schematically an embodiment of aphotometric section of the apparatus according to the invention, whichcan effect colorimetric, nephelometric and fluorometric analyses;

FIG. 42 is a cross section showing schematically another embodiment ofthe photometric section;

FIG. 43 is a perspective view showing an embodiment of a shuttermechanism shown in FIG. 42;

FIG. 44 is a side view illustrating an embodiment of the cuvette;

FIGS. 45A and 45B are schematic views illustrating an embodiment of thephotometric section in which the transmitted, scattered and fluorescentlights are received by a single light receiving element;

FIG. 46 shows another embodiment of the photometric section;

FIG. 47 illustrates still another embodiment of the photometric section;and

FIGS. 48A and 48B are schematic views illustrating another embodiment ofthe photometric section in which the scattered, transmitted andfluorescent lights can be received by a single element by using cuvetteshaving different configurations.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a schematic view illustrating a constructional principle ofthe automatic analyzing apparatus according to the invention. Thisapparatus can be classified as a discrete system adopting a batchprocess and belongs to a sequential multi system in which analyses for aplurality of test items can be effected continuously in succession.Sample vessels 1 are supported on a sample feed mechanism 2 and areintermittently fed in a direction shown by an arrow A. A given amount ofsample liquid, contained in the successive sample vessels 1 areaspirated by a sample delivery mechanism 3 at a given position inaccordance with test items to be analyzed and the given amount of sampleliquid is supplied into cuvettes 4 together with a diluent 5 asrequired. The cuvettes 4 are supported by a cuvette feed mechanism 6 andare intermittently fed along a reaction line B in a direction shown byan arrow B at a predetermined period, such as six seconds per step. Newcuvettes 4 are successively supplied to the feed mechanism 6 from acuvette-delivery mechanism 7. The cuvette 4 having the sample liquiddelivered therein is advanced by several steps and arrives at a givenposition at which point a reagent, dependent on the test item to bemeasured, is delivered in the cuvette 4 together with a diluent 9 bymeans of a reagent-delivery mechanism 8. Reagents to be used formeasurement are contained in reagent bottles 10₁ -10_(a) which aresupported on a reagent feed mechanism 11 movable in a reciprocal manneras shown by a double headed arrow C. A given reagent can be drawn by thedelivery mechanism 8 from the bottle which is positioned at the givendelivering position. The sample liquid and reagent can be sufficientlymixed by jetting the reagent into the cuvette 4 together with thediluent at a suitable flow rate. The cuvette 4 having had reagent andsample delivered thereto travels along the reaction line B. The testliquid in the cuvette is measured by photometers 12 to 15 eachcomprising a light source L and a light-receiving element S provided atpositions separated from each other by distances equal to multiples of atraveling step of the cuvette. In this manner the reaction state of thetest liquid in the cuvette 4 can be monitored as it progresses along thereaction line.

Particularly in a measurement of enzymatic reactions, it is veryimprtant to monitor the reaction over some extended period of time. Thatis to say, in the measurement of enzymatic reactions, it is impossibleto obtain an accurate result unless a measurement is effected during thelinear portion of an absorbance level-to-time characteristic curve. InFIG. 2, a typical reaction curve is shown and an absorption (O.D.) isplotted on the ordinate and time (t) measured from the addition ofreagent, is plotted on the abscissa. In FIG. 2, a left-hand zone (a)represents the lag phase of reaction due to heating time of test liquid,mixing, etc., and a zone (b) denotes the linear phase in which thereaction rate measurement, i.e. kinetic reaction measurement, can beeffected positively and accurately. Further a zone (c) represents an endpoint phase in which the reagent substrate or other given components inthe test liquid have been exhausted. Measurement in the end point zone(c) results in erroneously low values when performing kinetic assays.

The period of the linear phase (b) may be suitably changed by adjustingthe substrate concentration, etc. and total volume of test liquid. Thisadjustment is effected in such a manner that the end of the lag phase(a) can be detected by the photomesters 12 to 15 (see FIG. 1) for almostall test liquids even if the test liquids have fast or slow reactionrate. Preferably the substrate concentration conditions, and totalvolume of test liquid are so adjusted that the variation in absorptioncan be observed after twelve seconds (corresponding to the position ofphotometer 12) from the mixing of reagent and sample for the test liquidhaving the slowest reaction rate and the linear phase (b) will last forone or two minutes or more for the normal test liquids. By such ameasure, the lag phase of successively fed test liquids can be monitoredin a substantially completed state by the photometers 12 to 14. Itshould be noted that the photometers 12 to 15 can monitor the linearphase (b) as well as the lag phase (a). That is to say, when the end ofthe lag phase is detected for a test liquid by one of the photometers 12to 14, the measurement is effected for the relevant test liquid duringthe linear phase by means of a photometer which are situated beyond theabove mentioned photometer on the reaction line. After the measurement,the test liquid is discharged together with the cuvette 4.

The above mentioned sample feed mechanism 2, sample delivery mechanism3, cuvette feed mechanism 6, reagent delivery machanism 8, reagent feedmechanism 11 and the photometering sections can be controlled by acontrol device 16 including a computer on the basis of patientinformation introduced by an operator.

As described above, according to one aspect of the invention, the lagphase and linear phase are monitored at a number of positions on thereaction line to obtain a number of photometric data and then usefuldata are selectively derived from these data. By this measure it ispossible to obtain the analytical data of high accuracy and reliabilityand thus a useful automatic analyzing apparatus having excellent andunique abilities can be realized.

Now, embodiments of the apparatus according to the invention will beexplained.

FIGS. 3 and 4 are perspective views illustrating an outer appearance ofthe automatic analyzing apparatus according to the invention. A mainbody 25 includes a cover 26 hinged at the rear to provide access tointernal components. In the cover 26 are formed openings 27 fordissipating heat produced by light sources of photoelectriccolorimeters. A front plate 28 is secured to the main body 25 in such amanner that the front plate can be opened to provide access. A cuvettecontainer 29 for storing waste cuvettes and a waste liquid container 30for storing waste liquid are detachably secured to the front plate 28. Aright-hand side plate 31 is hinged to the main body 25 at the bottomside and a cassette holder 32 for supporting a detachable reagentcassette for holding various reagent bottles necessary for givenanalyses is provided on the side plate 31. A portion for fitting thecassette holder 32 defined by the right hand side plate 31 forms arefrigerator 33.

A sample liquid feed mechanism 34 is affixed to the main body 25 at itsfront portion. This mechanism comprises a rotating gear-like turntablewhich can be detachably installed in the apparatus when the cover 26 isopened. As shown in FIG. 4, a chain may be engaged with the turntable soas to feed the sample cups held by the chain. This chain may beselectively used, depending upon the number of test bodies to beanalyzed.

FIG. 5 is a schematic view illustrating an arrangement of variousportions of the apparatus with the top cover 26 removed. The sample cupsare fed successively by the feed mechanism 34 to a given aspirationposition. The cuvettes are fed one by one by a cuvette supply mechanism35 through a position near the sample aspiration position. A givenamount of sample from the sample cup is supplied to the cuvette by apump 36. While the cuvette is fed to a photometric position by a cuvettefeed mechanism 37, a given amount of a suitable reagent is supplied tothe cuvette from a reagent bottle 38 in the reagent cassette 32 by meansof a reagent dispenser 39. A plurality of reagent bottles 38 arearranged in the cassette 32 along an endless path and any desired bottle38 can be indexed at a position for aspirating the reagent therein bythe dispenser 39. As will be explained later in detail, an ion sensor 40is arranged along the cuvette feed mechanism 37 to measureconcentrations of ions in the test liquid. At the end of the cuvettefeed mechanism 37 a distributing mechanism 41 is arranged forcontinuously delivering successive cuvettes into right and leftphotometering sections 42A and 42B alternately. These photometeringsections are communicated with the openings 27A and 27B, respectivelyformed in the cover 26. After the measurement in the sections 42A, 42B,the cuvette and its container are discharged at stations 43A and 43B.

When two photometering assembles 42 are provided even if the cuvettesare successively fed every six seconds by means of the feed mechanism37, each test liquid can be measured for twelve seconds at eachphotometer position by either one of the photometering sections andthus, the time available for measurement can be increased. Further, evenif one of the photometering assemblies becomes inoperative, theanalyzing operation can be carried out.

Next, a detailed construction of the photometering section will beexplained. As illustrated in FIGS. 6 and 7 the photometering section 42comprises a disc-shaped turntable 44 surrounding a chimney 27. Aplurality of cuvettes are arranged along the periphery of the turntable44. These cuvettes can be indexed past a number of photometeringpositions. The cuvette 45 is made at least partially of transparentmaterial. A single light source 46 is arranged in the chimney 27 and anumber of apertures 47 are formed in a cylindrical body defining thechimney 27 at positions corresponding to a number of photometeringpositions. These apertures are situated at the same vertical level asthe light source 46. Around the cylinder forming the chimney 27 isrotatably arranged a drum 49 having formed a pair of slits 48 therein atthe same level as the apertures 47. The The drum 49 is rotated by amotor 50 at a high speed. There are further arranged a number of opticalfibers 51 each having one end secured at a respective photometeringposition so as to receive a light emitted from the light source 46through the aperture 47 and the slit 48 and transmitted through thecuvette 45. The other ends of these respective fibers are collected atone or two positions and are faced to photo detectors 52 comprising aphotomultiplier tube or similar device. Between the collected ends ofthe fibers 51 and the photo detector 52 is arranged a rotary filter unit53. As shown in FIG. 8, the rotary filter unit 53 comprises a pluralityof filters λ₁ to λ₁₀ having different transmitting wavelengths and isrotated by a motor 54 to index a desired one into the light path betweenthe distal end of the optical fibers 51 and the photomultiplier tube 52or similar device. Output signals from the photo detectors 52 aresupplied through an A/D converter 55 to a computer 56 provided in thecontrol device 16.

In FIG. 6, it is assumed that the turntable 44 supports, for examplethirty cuvettes 45 which are advanced at an interval of, for instance,ten seconds, and the filter unit 53 is rotated by one revolution duringthese ten seconds. Then, each of the filter elements λ₁ to λ₁₀ passesthrough the light path reaching the photo detector 52 for about onesecond. During this one second, the drum 49 having formed the slits 48therein is rotated by one turn. In this manner, absorption data for allwavelengths can be obtained at each photometering position. From theseabsorption data are selected desired data corresponding to a givenwavelength or wavelengths which are determined by the test item, and theselected data are converted into digital values which are then stored inthe computer 56. In this manner, for each test liquid in each cuvette onthe turntable, the reaction data can be obtained from all photometeringpositions every ten seconds. Hence, absorbance data for any given testliquid in any given cuvette can be made available at any or allavailable wavelengths every ten seconds for as long as the cuvette andtest liquid remains on the turntable. In the computer, the linear phasewhen pertinent, can be determined from this data, and thus the kineticreaction data, if necessary, can be obtained accurately.

As shown in FIG. 9A, the linear phase can be determined at a sectionnear a trigger addition point and having a small value of |A-B|. Inorder to obtain a reaction curve shown in FIG. 9B, it is necessary tocompensate for differences in outputs from the photometering positions.To this end, prior to the measurement, a calibrating cuvette havinghighly accurate optical length is set in the apparatus and absorptionvalues of this cuvette for all wavelengths are measured at allphotometering positions and are stored in the computer. During themeasurement, the stored absorption values are subtracted from detectedvalues. In this manner, the reaction curve illustrated in FIG. 9B can beobtained.

By increasing the rotation speeds of the rotary filter unit 53 and theslit drum 49, a corresponding increase in data may be obtained from eachmeasuring position.

FIG. 10 is a chart showing the operation of the apparatus according tothe invention.

While FIGS. 6 and 7 show two sets of the slit, filter assemblies, andphoto detectors, any number of such optical channels may be provided.

It should be noted that since in this embodiment use is made ofsequential multi-test mode, it is, of course possible to measurecontinuously a plurality of test items for each sample as desired by theoperator, and supplied to the computer-control device via keyboard,cards or other commonly used computer input devices, etc.

It should be noted that this embodiment offers an operator a number ofchoices which heretofore would require a sacrifice in productivityand/or convenience to obtain the desired combination of data gatheringmodes and/or capabilities as follows:

A. Monitoring the change in absorbance of a test liquid over time withcapabilities for selectively determining the linear phase of thereaction.

B. Performing such monitoring as in `A.` above at two or morewavelengths.

C. Gathering data for test liquids at only one or two points in time(herein referred to as end-point assays) at one more wavelengths whensuch desired test liquids are randomly interspersed on the turntablewith test liquids requiring data gathering modes as in `A.` or `B.`above.

D. Conversely, test liquids requiring data gather modes as in `A.` or`B.` above can be randomly interspersed on the turntable with end pointassays as in `C.` above.

E. It is further possible to effect continuously a single test item forall samples utilizing any or all of data modes `A.` through `C.` aboveor;

F. To treat a plurality of samples to a plurality of test itemsutilizing any or all of the data acquisition modes as in `A.` through`C.` above.

The apparatus of this embodiment further includes the ability forautomatic calibration. This can be effected by setting a standard sampleto the sample feed mechanism 34 during a stand-by condition. Then, theapparatus automatically operates at every constant time period and thestandard sample is delivered into the cuvette 45 on the cuvette feedmechanism 37 and the automatic calibration is effected in a usual mannerto compensate for drifts of the apparatus such as variation inbrightness of the light source 46, etc.

This automatic calibration ability allows the instrument to be used atany time of day or night with complete confidence that the calibrationroutine is properly performed regardless of the relative expertise orattention of the operator.

The control of operation of various portions, the inputting operation ofpatient or sample information, and the calculation of the analyzedresults can be effected by a control device (not shown) including one ormore computers.

FIG. 11 is a perspective view illustrating an embodiment of the cuvette45. The cuvette 45 of this embodiment comprises a rectangular opening45a and a supporting flange 45b provided at the periphery of opening.The opening is connected to a bottom portion 45c by a tapered side wallnarrowing towards the bottom portion. The bottom portion 45c is formedas a semicylindrical shape and has measuring windows 45d at both ends,when viewed in its axial direction, through which windows the testliquid in the cuvette is optically measured.

According to the above mentioned construction of cuvette 45, since theopening 45a (receiving port) is wide, it is possible to easily deliverthe sample and reagent without sputtering them externally. Further, theamount of the test liquid is sufficient to fill the semi-cylindricalbottom portion 45c, and thus the analysis can be effected with verysmall amounts of the sample and reagent. Moreover, since a measurementaxis extends in a longitudinal direction of the cuvette and this issufficiently long, it is possible to carry out the analysis with veryhigh sensitivity. Since the side wall is tapered from the opening 45a tothe bottom 45c, and the flange 45b is provided around the opening, thecuvette may be simply secured to the cuvette feed mechanism 37 in amanner shown in FIGS. 12A and 12B. That is, the flange 45b may be placedon a holding member 60 as illustrated in FIG. 12A or may be detachablyinserted into recesses formed in a holding member 61 as depicted in FIG.12B. In this manner, the cuvette 45 may be simply supported by theholding member without making the measuring windows 45d in contact withthe holding member 60 or 61, and thus the measuring windows can beprotected against injury. In FIG. 12A, an arrow E denotes the measuringoptical axis. Further, the cuvette 45 may be formed by molding oftransparent material, and thus its mechanical strength can be made high.

Next, the sample and reagent delivery mechanisms will be explained.Since these mechanisms can be constructed substantially similarly toeach other, only the reagent delivery mechanisms will be explained.

As illustrated in FIG. 5 in this embodiment, a plurality of reagentbottles 38 are arranged in the reagent cassette along an endless path.That is to say, as shown in FIGS. 13 and 14, the cassette comprises anelliptic outer frame 80 in which are arranged rotatably a pair ofpulleys 81 and 82. An endless belt 83, preferably a timing belt, isarranged between these pulleys 81 and 82. A plurality of partitions 84are integrally formed with the belt. The reagent bottle 38 is removablyinserted into a space formed by adjacent partitions and the outer frame80. One of the pulleys 81 has formed in its bottom surface, recesseswhich engage detachably with projections 86 formed on an output shaft ofa stepping motor 85 secured to the main body 25. The stepping motor 85may be driven in either a forward and/or backward direction asdetermined by means of an externally supplied signal. A handle 87 issecured to stationary shafts of the pulleys 81 and 82 so that thecassette can be easily set into, or taken out of, the holder 32.

In order to maximize the operational efficiency of the analyzingapparatus in which several reagents selected from a number of reagents,are delivered by a single delivery pump, it is preferable to effect thedelifery of reagents in such an order that the total traveling distanceof the cassette is minimized. For this purpose, the stepping motor 85for transporting the reagent bottles 38 is of a reversible type.

As illustrated in FIG. 15, information about the order of arrangement ofreagent bottles in the cassette has been previously stored in a testitem order determining unit. Upon an initiation of measurement for aparticular test item, test item data to be effected for the relevanttest item is supplied from a memory to the test item order determiningunit, to which is also supplied information about a particular reagentbottle which is now in the reagent aspiration position in the reagentbottle transfer device. In the determining unit, the test item order isdetermined on the basis of these three pieces of information in such amanner that the traveling distance of cassette in the holder can beminimized, and a list for denoting the determined test item order isformed. In accordance with this list the order determining unit controlsthe successive alignment of reagent bottles with the reagent aspirationstation in a sequence so as to insure the optimum economy of movement onthe part of the cassette. At the time the list is generated, the list isalso supplied to the photometric section, so as to provide thephotometric section with test item data relevant to the photometer'sresponsibilities, for example, the overall sequence of test items andsamples on the turntable.

In the above embodiment, all the reagent bottles are arranged in arefrigerator in order to avoid an alternation or deterioration of thereagents. However, some reagents might precipitate under a lowtemperature and thus should not be stored in the refrigerator. In such acase, as shown in FIG. 16, the cassette holder 32 is divided into twoportions, 32A and 32B. One portion (32A) is maintained at roomtemperature, and reagents which should not be stored at low temperaturesare installed in this portion 32A. The other portion (32B) is connectedto a refrigeration machine 96 and blower 97, to form a closed loop. Theoperation of the refrigeration machine 96 is controlled by atemperature-detecting element 98 in holder 32B, and a control circuit 99which receives the output signal from temperature detector 98. It shouldbe noted that the cassette shown in FIGS. 13 and 14 may be installed inportions 32A and 32B. In order to prevent the escape of cool air fromrefrigerator portion 32B, portion 32B comprises a lid 100 (illustratedin FIG. 17). A small aperture 101 is formed in the lid at a positioncorresponding to the aspiration position so that a fluid dispensingprobe can be inserted into and retracted from portion 32B. The fluidwhich is used to calibrate the apparatus is preferably stored inrefrigerator portion 32B.

In the reagent delivery mechanism as shown in FIG. 18, only a singlepump 105 is able to deliver a plurality of different reagents.

In this embodiment, use is made of reagents of high concentration andthe reagents are jetted into the cuvettes from the probes together withappropriate diluent(s). By utilizing this construction, the wholeapparatus can be made small in size and contamination between thedifferent reagents can be avoided because the inside of probe is washedby the diluent(s). Since diluent(s) is/are heated to a temperature nearthe reaction temperature, the temperature of the test liquid can berapidly increased, and the reaction time can be shortened even if therefrigerated reagent is used and the reaction is carried out in atemperature-controlled incubation environment having a low thermalefficiency, such as an air bath. Further, if the diluent is the sameliquid as any required buffer solutions, it is not necessary to provideseparate delivery pumps for these liquids.

To begin a dispensing cycle, the desired reagent bottle 38 in thecassette 80 is transported to a position just below the aspirationposition of the probe 106. A preheating device 107 is provided to heatthe diluent to a temperature near the desired reaction temperature andcomprises a heater, a temperature sensor and a temperature controlcircuit (not shown). The syringe 105 is connected to the probe 106 and adiluent bottle 108 via valves 109 and 110, respectively. In thisembodiment, these valves are denoted as two-way valves, but they may bereplaced by a single three-way valve. Since these valves 109 and 110 arekept in contact with the diluent only, they do not require chemicalresistance. However, in view of a very small amount of liquid to bedelivered it is desired that a volume inside the path be kept withinvery narrow and precise limits. To this end, it is preferable toconstruct the valves 109 and 110 by use of a rotary solenoid valve witha tapered cock.

The syringe and piston constructing the pump 105 do not require specialchemical resistance properties because like the valves 109 and 110 theycontact only diluent liquid. In order to deliver different amounts ofreagents by the same pump 105 the piston of the pump can be displaced bystrokes of variable length by a pulse motor energized by an externalsignal. As the diluent use may be made of buffer solution as explainedabove or in some cases use may be made of de-ionized or distilled water.

Operational steps of the reagent delivery pump will be denoted in thefollowing table.

    __________________________________________________________________________                          Valve 109                                                                           Valve 110                                                                           Syringe 105                                 Step      Position of probe 106                                                                     position                                                                            position                                                                            piston motion                               __________________________________________________________________________    Form air bubble at                                                                      Stand by position (in air)                                                                Open  Closed                                                                              Withdraw slightly                           probe tip                                                                     Probe into reagent                                                                      Stand by position →                                                                Closed                                                                              Closed                                                                              None                                                  in reagent                                                          Aspirate reagent                                                                        In reagent  Open  Closed                                                                              Withdraw to                                                                   aspirate reagent                            Transport probe                                                                         In reagent →                                                                       Closed                                                                              Closed                                                                              None                                        above cuvette                                                                           above cuvette                                                       Deliver reagent and                                                                     Above cuvette                                                                             Open  Closed                                                                              Close to dispense                           diluent into cuvette                                                          Aspirate diluent                                                                        Above cuvette →                                                                    Closed                                                                              Open  Withdraw to                                           stand-by position       aspirate diluent                            __________________________________________________________________________

When different diluents are used for different reagents, or when areagent is delivered at several positions, a plurality of delivery pumps105A to 105D may be provided for each diluent as shown in FIG. 19. Whena cuvette 45 is transported to a delivery position corresponding to anyone of the pumps 105A to 105D, for example 105A, and the reagent to bedelivered to this cuvette is that which should be diluted by a diluentconnected to this pump 105A, the related reagent bottle 38 is fed to aposition corresponding to the pump 105A and then a given amount of thedesired reagent is delivered into the cuvette 45 by the pump 105A. Onthe contrary, if the reagent to be delivered to this cuvette is thatwhich should be diluted by a diluent connected to the pump 105C, afterthe cuvette is further advanced by two steps, the desired reagent isdelivered into the cuvette 45 by the pump 105C.

According to the above explained construction of the reagent deliverymechanism, since the diluents or buffer solutions which are optimum forrespective diluents can be used, the reagents can be maintained in astable condition for a longer time, and the number of possible testitems can be increased. For some reagents it is preferable to effectdelivery thereof by several stages in order to effect storage of thereagents as component parts in such a way as to prolong the usefulchemical stability of these reagents or to dispense quantities which maybe beyond the useful dynamic range of a given pump 105A to 105D. In sucha case, the same reagent or its component part may be delivered into thesame cuvette by a succession of pumps 105A to 105D at successive steps.

In such a discrete delivering operation it is quite important to assurewhether a given amount of liquid has been aspirated or not. That is tosay, if a serum, sample, or reagent is aspirated excessively orinsufficiently, erroneous data would be obtained. Therefore, such asituation must be checked by some means.

FIG. 20A is a schematic perspective view illustrating an embodiment ofsuch means for detecting an amount of aspirated liquid. In thisembodiment, the probe 106 is made of transparent material and a lightemitting element 110 and a light receiving element 111 are arranged onrespective sides of the probe 106. In the probe 106 there are liquid 112such as a reagent or sample, an air layer 113 and a diluent 114, thesematerials having different absorptions. Therefore, a transmittivity Trepresented by an output from the light receiving element 111 changes asshown in FIG. 20B, depending upon a volume Q of the aspirated liquid112. From this output T it is possible to detect whether or not acorrect amount of liquid has been drawn in the probe.

In an embodiment shown in FIG. 21A, a pair of electrodes 115 and 116 arearranged in the probe 106 with interposing a given distancetherebetween. When a correct amount of the liquid 112 has been aspiratedin the probe, these electrodes 115 and 116 are conductively connected toeach other via the electrically conductive liquid so as to identify thecorrect amount of liquid. FIG. 21B illustrates a characteristic curvedenoting a relation between the amount of aspirated liquid Q, and aresistance value R, between the electrodes.

In another embodiment illustrated in FIG. 22A, a pair of plate-shapedelectrodes 117A and 117B are arranged on either side of the probe 106 soas to form a capacitor. The capacitance between plates 117A and 117Bwill be a function of the liquid level in the probe 106. The capacitoris connected to a CR oscillator 119 which will change frequency ascapacitance changes. Liquid level in probe 106 will now be determined byfrequency of CR oscillator. The output frequency of the oscillator fvaries as a function of an amount Q of the liquid 112 (see FIG. 22B).The output signal is counted by a counter 120 and an output from thecounter is supplied to a discrimination circuit 120 to determine whetherthe amount Q of the aspirated liquid 112 is correct or not.

When the reagent is aspirated by the reagent delivery probe which isimmersed in the reagent as explained above, it is preferable to detectthe level of the reagent in the bottle so as to control the depth ofthat portion of the probe which is immersed in the reagent. FIG. 23 is aperspective view showing schematically an embodiment of such a liquidlevel detector. In this embodiment, the reagent bottle 38 is made oftransparent material and a light-emitting device 125 and alight-receiving device 126 are arranged on respective sides of thebottle 38. These devices comprise a plurality of light-emitting andreceiving elements, respectively, arranged side by side in the verticaldirection, and the liquid in the bottle 38 can be detected by outputsignals from these light-receiving elements. With the aid of thesesignals the immersed depth of the probe 106 of the reagent delivery pump105 can be controlled in a desired manner.

By the above explained measure, it is possible to draw positively agiven amount of reagent with inserting the probe 106 into the reagent bythe minimum required depth and thus, an amount of reagent adhering tothe outer wall of probe can be minimized. Therefore, the tip of probecan be easily and positively washed, and any contamination between thereagents can be effectively eliminated.

The liquid level detector may be constructed as illustrated in FIG. 24.In this embodiment, a holder 127 is secured to the probe 106 and alight-emitting element 128 and a light-receiving element 129 areprovided at respective ends of arms of the holder 127. The reagentbottle 38 is made of transparent material. By lowering the holder 127together with the probe 106 the liquid level of the reagent in thebottle 38 can be photoelectrically detected.

Next, a device for cleaning the probe of the reagent delivery pump willbe explained. FIG. 25 is a schematic cross section illustrating anembodiment of such a cleaning device. In this embodiment, a ring 130having a plurality of openings in its inner wall is connected through awaste liquid bottle 131 to a vacuum pump 132. The probe is inserted intothe ring 130 and the pump 132 is energized to aspirate a liquid adheringto the outer surface of the probe into the bottle 131.

FIG. 26 is a perspective view illustrating another embodiment of thecleaning device. In this embodiment, by piercing the probe through ablotter, a reagent on the outer surface of the probe can be removed. Tothis end, a supporting plate 133 is arranged above the reaction line ofcuvette feed mechanism 37 in parallel with the reaction line. Thesupporting plate 133 has formed therein an opening 134 for passing theprobe, and a blotter 135 is passed through the opening. The blotter 135is wound onto a roll which is rotatably supported at one end of theplate 133. At the other end of the plate a motor 136 is provided whichtakes up the blotter 135. It should be noted that a suitable load may beapplied to the blotter roll so as to avoid looseness of the blotter.Upon delivering the reagent, the probe 106 is inserted into the cuvette45 on the reaction line through the blotter 135 and the aperture 134.

In this embodiment, a pair of arms 137a and 137b are rotatably journaledto the supporting plate 133 and the probe 106 is rotatably supported atthe free ends of arms by means of pins 138a and 138b. To one of the arms137b is coupled a motor 139. The probe 106 can move between the arms137a and 137b into the reagent bottle 38 at the reagent aspiratingposition as shown in FIG. 27A, as well as into a position above thecuvette 45 through the blotter 135 and the opening 134, as illustratedin FIG. 27B. In this case, it is preferable to use the liquid leveldetector shown in FIG. 23.

In the above explained probe-washing device, since it is not necessaryto use a wash water, the construction becomes simple, and the probe 106can be completely cleaned in conjunction with the liquid level detector.

The above explained probe-washing device and its transporting mechanismmay be also applied to the probe of the sample delivery mechanism 36.

Next, a control device for controlling the actions of each portion ofthe analyzing apparatus, introducing test body information, treating anddisplaying analyzed results and the like will be explained. As statedabove, in the present embodiment, the control device is arranged apartfrom the analyzing apparatus itself. When the analyzing apparatus isseparated from the control device, (1) when the analyzing apparatus isinstalled in a laboratory hospital or the like which has a computer ofsufficient capacity, the analyzing apparatus can be controlled bysupplying appropriate software to this computer, (2) in case a dedicatedcontrol device becomes out of order, by selectively connecting theanalyzing apparatus with a transmission circuit, the analyzing apparatuscan be operated by a back-up computer connected through the transmissioncircuit, and (3) in case an increase in productivity is necessary, asingle control device can operate a plurality of analyzing apparatusesby adding one or more analyzing apparatuses to the analyzing apparatusalready in operation.

The constructions for carrying out the above functions (1) to (3) willbe explained in order. FIG. 28 is a block diagram showing theconstruction of an automatic analyzing apparatus according to thepresent invention, in which control of the automatic analyzing apparatusis switchable between a dedicated control device and some other computersystem such as a lab's host computer system. A dedicated control device140 comprises a computer 141 and an interface 142 and is connected to ananalyzing apparatus 25 through a switching device 143. Further, analternate computer 144 can be connected to the analyzing device 25through an interface 145 and said switching device 143. In this manner,the switching device 143 is automatically or manually operated, and theanalyzing appartus 25 is connected to either the dedicated controldevice 140 or the alternate computer 144.

According to such construction, if the dedicated control device 140 isdown, the alternate computer 144 can serve as back-up by operating theswitching device 143, so that there is no interruption in analyzingoperation. Further, the computer 144 can be operated without affectingthe dedicated control device 140.

FIG. 29 is a block diagram showing another embodiment of the system,including the automatic analyzing apparatus according to the presentinvention, in which the automatic analyzing apparatus is connectablewith a back-up computer through a communication line. Like numeralsindicate like parts as shown in FIG. 28. A back-up computer 144 isconnected to a communication line 147 through an interface 145a and aMODEM 146a. This back-up computer 144, interface 145a and MODEM 146a areinstalled in a service company, maker, or the like. On the side of theprovisions provided with the analyzing apparatus 25, is provided a MODEM146b connected to said communication line 147 and further connected tothe switching device 143 through an interface 145b. In this manner, theswitching device 143 can be automatically or manually operated, and theanalyzing apparatus 25 is then connected to either the back-up computer144 or the dedicated control device 140.

According to such construction, as described above, even if thededicated control device 140 becomes out of order, the back-up computer144 can operate the analyzing apparatus 25 through the communicationline 147 until repair is completed so that there is prolongedinterruption in analyzing operations.

FIG. 30 is a block diagram showing still another embodiment of thesystem comprising the automatic analyzing apparatus according to thepresent invention, in which one control device can operate a pluralityof analyzing apparatuses. In this embodiment, like numerals indicatelike parts as shown in FIG. 28. In this embodiment, a computer 141 inone dedicated control device 140 can be connected to one analyzingapparatus 25 through an interface 142 as well as to an additionalanalyzing apparatus 25' through an interface 142'.

According to such construction, a plurality of the analyzing apparatuses25, 25' can be controlled by the single control device 140 so thatproductivity can be increased expeditiously and economically.

A patient data system for use with an automatic analyzing apparatusaccording to the present invention will be explained.

In a conventional automatic analyzing apparatus, a commonly used patientdata system begins with a test requisition form which, in a clinicalsetting, is usually filled out by, or under the direction of, a givenpatient's attending physician. This filled-in requisition form includesthe patient's name and/or an identifying number and the tests for whichthe sample must be analyzed as minimum information.

The various test requisition forms are used to prepare a loading list.The loading list describes each sample's identification (by name and/ornumber) and its position on the instrument's sampler and/or its place inthe sample queing. Test results are generated in the same sequence assamples are introduced, and the relationship between test results andthe corresponding patient can be determined from the loading list. Theanalytical results can be manually transferred to the requisition slipfor use as the report form ultimately returned to the attendingphysician or; the patient identification information can be manuallytransferred to the standard instrument report form or; both theanalytical results and the patient information can be manuallytransferred to yet another form to serve as the physician's report.

In such a patient data system, however, it is necessary to copy theanalytical results and/or patient information. Further, in case ofdeleting or adding a sample, or inserting a stat (urgent) sample bysqueezing it between samples, the relation between the analyzed resultsand the loading list changes and the following mistakes can occur.

1. Mistaken match of sample number to patient name.

2. Posting mistake of patient information and/or analytical results.

3. Mistaken match of sample aliquot to identification name and/ornumber.

4. Proper match of sample and identification number, but mistaken matchto patient name.

Another common patient data system involves transferring patient datafrom the requisition form into a computer memory and printing it outtogether with analytical results. In this system, however, the patientinformation must be transferred manually by means of a keyboard, so thatit is subject to a loading mistake. In yet another system, test itemselection information is automatically loaded into a computer memoryfrom a requisition card, but sample I.D. is manually collated with apatient, so that there is the possibility of a mistake similar to thosedescribed above.

Conventional automatic analyzing systems frequently include as part ofthe instrument report form some means for flagging or highlightingabnormal test results. Usually an expected range of values arepredetermined and any test result outside this range of values issomehow flagged as `abnormal` on the instrument report form. However,patient populations differing by such things as age, sex, or the like,will have different expected ranges. For improved diagnosticinformation, it would be more appropriate to compare a given patient'sresults against those of an appropriate population.

The patient data system for the automatic analyzing apparatus accordingto the present invention eliminates various inconveniences in the abovedescribed conventional data systems while improving upon the integrityof data by reducing opportunities for error to occur.

The data system of the present invention utilizes a copy of thephysician's original requisition form to obtain pertinent patient dataand test selection information. The same form is used to provide aninseparable link between patient name and sample number and to serve asthe instrument report form which includes patient identification data,sample number, analytical results, population appropriate expectedranges, and abnormals flagging (when appropriate). As a result of thisdata system, the possibility for the above mentioned errors has beeneliminated. In addition, this system reduces the amount of paper whichmust be handled and consumed since the present invention uses theoriginal test requisition form as the report form.

FIGS. 31 and 32 are flow charts of a patient data system of theautomatic analyzing apparatus according to the present invention. FIG.33 is a plan view showing a format of a patient card used in suchsystem. The flow chart shown in FIG. 31 indicates that the variousexpected ranges by test item and population parameters (sex, age,medical prescription, and the like), have been previously stored in theanalyzing apparatus and expected values corresponding to the patient'sappropriate parameters are printed on the requisition/report form. Onthe requisition/report form, the analytical results and judgementsobtained by comparing the analytical results against appropriateexpected range values are also printed out. In the flow chart of FIG.32, the patient information and the expected range values correspondingto the relevant patient have been previously recorded on therequisition/report form and the analytical results and judgements aresubsequently printed on the form. In this case, the requisition/reportform is fed through the reader/printer twice. During the first feed, thetest item selection information and the patient's expected rangepopulation parameters corresponding to an identifying number are readout and appropriate expected ranges are printed on the form. As shown inFIG. 33, use is made of a bar code for the identifying number. Whenabnormal analytical values are detected, judgements are printed in an AF(Abnormal Flags) column with marks for indicating the direction ofdeviation from the expected range and an amount of abnormality (forexample: the number of standard deviations the analytical result differsfrom the mean expected value.)

Next, a mechanism for disposing of cuvettes and test liquids afterphotometric measurement will be explained. In this embodiment, wasteliquids are not discharged from the analyzing apparatus. In theapparatus is provided a waste liquid handling mechanism for pretreatingchemical wastes before allowing their removal from the system so as tofacilitate their disposal via environmentally responsible means.

FIG. 34 is a schematic diagram showing an embodiment of such a disposalmechanism. The cuvette 45 is held by the supporting mechanism at eachphotometric position of the photometric measurement section. Aftermeasurement, the supporting mechanism is driven and the cuvette 45 isallowed to fall (as shown in FIG. 34 by an arrow). Underneath thecuvette 45 is arranged a duct 500 on which a mesh 501 is in an inclinedfashion. The falling cuvette 45 strikes the mesh 501 and the content ofcuvette is spilled into a neutralizing tank 502. The cuvette 45 slidesdownward on the mesh 501 until it is allowed to fall into the cuvettewaste tank 29. In the neutralizing tank 502, the pH value of the wasteliquids is adjusted and noxious substances are removed. The filtrationis then passed to the waste liquid container 30. The neutralizing tank502 is arranged in such a way as to be conveniently removable and if itstreating ability is diminished, it may be regenerated or exchanged.

According to such a disposal mechanism, even if the waste liquid istemporarily stored in the container 30, annoying odors due to noxioussubstances would not be produced. Additionally, solid and liquid wastesare conveniently separated for disposal.

FIGS. 35 and 36 are schematic views illustrating two other embodimentsof disposal mechanism. In FIG. 35, the cuvette 45 falling from thecuvette-supporting mechanism is received by a cuvette container 29'having secured a mesh 29a' at its bottom, and the waste liquid issupplied into the container 30. Since the cuvette 45 has a shape shownin FIG. 11, it rolls easily. Therefore, the liquid in the cuvette can becompletely discharged. FIG. 36 shows the construction similar to thatshown in FIG. 35, except that the falling cuvette 45 is positivelyturned on the inner wall of a cuvette container 29". To this end, aninclined side wall 29a" of the container 29" is provided beneath thepath of a falling cuvette and discontinuous projections 29b" are formedin the inner surface thereof.

According to such constructions similar to that in FIG. 34, solid andliquid wastes can be automatically separated to facilitate wastetreatment and disposal.

It should be noted that the present invention is not limited to theembodiments mentioned above, but many modifications can be conceivedwithin the scope of the invention. For instance, in the aboveembodiment, the lag phase is monitored before the photometricmeasurement in the linear phase is effected, but the end point may bemonitored by the lag phase monitoring section and after the end pointhas been detected, the photometric measurement may be carried out. Inthe embodiment, after the detection of the end of the lag phase by themonitoring section, the test liquid is removed from the reaction linetogether with the cuvette and the precise measurement is effected.However, as shown in FIG. 37, it is possible to transport the testliquid alone from the reaction line to the precise measuring section. InFIG. 37, a suction nozzle 150 is arranged movably from the cuvette 45 onthe reaction line to a washing bottle 151. The nozzle 150 is connectedto a syringe 153 through a heat-insulated tube 159 and a flow-typephotometric cuvette 152. The syringe 153 is coupled to a suction pump156 via a valve 154 and a waste liquid tank 155. A precise measuringphotometer comprises a light source 157 and a photoelectric converter158 arranged on respective sides of the photometric cuvette 152. Thevalve 154 is closed and the nozzle 150 is immersed into the test liquidin the cuvette 45 on the reaction line after the content of the cuvettehas been detected to be in the linear phase, and the syringe 153 isoperated to draw a given amount of the test liquid. Then, the nozzle 150is moved into the washing bottle 151 and the syringe 153 is operatedagain to aspirate a washing water so that the previously aspirated testliquid is fed into the photometric cuvette 152. Then, the aspiratingoperation of washing water is stopped and the precise measurement iseffected by means of the photometer 157 and 158, while the test liquidis in the cuvette 152 stationarily. After measurement, the valve 154 isopened and the pump 156 is energized to discharge the test liquid andwashing water aspirated in the cuvette 152 and the tube 159 into thetank 155. During this operation, the syringe 153 is returned in itsinitial position. Since the suction nozzle 150 and the photometriccuvette 152 are washed with water after measurement, any contaminationdoes not occur. The suction and measurement may be carried out in themanner mentioned below. At first, the valve 154 is closed and thesyringe 153 is operated to draw the test liquid into the cuvette 152.Then, the precise measurement is effected. After the measurement, thevalve 154 is opened and the pump 156 is driven to suck the washingwater. At the same time, the syringe 153 is returned to the initialstate. Also in this case, the precise photometric measurement can beeffected without any contamination.

To improve upon analytical capabilities of the present invention it isfurther possible to provide an ion activity measuring device at anyposition on the reaction line after the reagent delivery so as tomeasure concentrations of ions of such potential test items as Na, K,Cl, etc. FIG. 38 illustrates an embodiment of such a device. In thisembodiment, a plurality of ion selective electrodes 160 are immersed inthe cuvette 45 set in the cuvette feed mechanism 37 (reaction line) tomeasure the ion concentration. These electrodes 160 are secured to oneend of an arm 161, to the other end of which is secured a pair of guiderods 162a and 162b, which are inserted so as to allow movement insleeves 164a and 164b, respectively, provided in a supporting plate 163.At the free end of the guide rod 162a is journaled a roller 165, whichis urged against an eccentric cam 167 which is secured to a drivingshaft of a motor 166. In order to avoid dust contamination, the ionactivity measuring device is protected by a cover 168. As the cam 167 isrotated by the motor 166, the arm 161 moves up and down vertically,while it remains horizontal owing to the sleeves 164a and 164b. When thearm 167 is lowered, the ion selective electrodes 160 are immersed in thetest liquid in the cuvette 45 to measure simultaneously various ionactivities.

FIG. 39 is a schematic view illustrating another embodiment of the ionactivity measuring apparatus. In this embodiment, the test liquid in thecuvette 45 is aspirated by a nozzle 170 into a flow cell 171 in whichvarious kinds of ions can be detected. The nozzle 170 is secured to oneend of an arm 172, the other end of which is secured to a guide rod 173.The guide rod 173 is inserted so as to allow movement in a sleeve 174which is secured to a supporting plate. A roller 175 is secured so as toallow rotation at one end of the guide rod 173, and is urged against aneccentric cam 177 which is secured to the driving shaft of a motor 176.When the cam 177 is rotated by the motor 176, the nozzle 170 is immersedinto the test liquid in the cuvette 45. The nozzle 170 is connected to asyringe 179 through a flexible tube 178 and a flow cell 171 and to asuction pump 182 through a valve 180 and a waste liquid tank 181. Theion selective electrodes 183 are arranged in such a manner that theirmeasuring surfaces project into the flow cell 171. In order to protectthe apparatus against dust, a cover 184 is provided. At first, the valve180 is closed and the nozzle 170 is immersed into the test liquid in thecuvette 45 on the reaction line by energizing the motor 176. Then, thesyringe 179 is operated to aspirate a desired given amount of the testliquid in the cuvette 45 into the flow cell 171. Under such a condition,concentrations of various ions in the test liquid are quantitated by theion selective electrodes 170. After measurement, the valve 180 is openedand the pump 182 is energized to discharge the test liquid into the tank181 and the syringe 179 is returned to its initial position.

FIG. 40 is a block diagram showing an embodiment of a signal processingcircuit of the above mentioned ion activity measuring device. Outputsignals from the ion selective electrodes 160 (183) are amplified in apreamplifier 185 and then are converted into a digital signal by ananalog-digital converter 186. The digital signal thus obtained issupplied to a control device 187 and is processed in a desired mannertherein.

In the ion activity measuring device shown in FIGS. 38 and 39, a blottermay be arranged above the reaction line as illustrated in FIG. 26 andthe ion selective electrodes 160 and the nozzle 170 may pierce theblotter. Alternatively, a wash bottle may be arranged apart from thereaction line as depicted in FIG. 37 and the ion selective electrodesand the nozzle can be immersed in this bottle. In this manner, the ionselective electrodes and the nozzle can be cleaned so as to avoid anycontamination between successive test liquids and thus very accuratemeasurement can be conducted.

Further, in the above embodiments, the measuring section 42 is soconstructed as to analyze test items in a test liquid by means of astandard photometric method, but use may be made of nephelometric andfluorometric methods in addition to the standard photometric method. Insuch a case, a light-receiving element 52' for receiving scatteredand/or fluoroscent light, may be arranged underneath the cuvette 45 inthe required measuring position as shown in FIG. 41. The light-receivingelement, a photodetector device 52', may be arranged underneath therotary filter unit 53 shown in FIGS. 7 and 41 and may be effectivelyopposed to the cuvette 45 by means of optical fibers 51.

Outputs from these photodetectors 52 and 52' are supplied to ananalog-digital converter 55 through a multiplexer 190. Further, as shownin FIG. 42, a common photodetector 52 for photometric measurement may beused also for nephelometric and/or fluorometric measurements with use ofa shutter mechanism shown in FIG. 43 is made. This shutter mechanismcomprises a guide plate 191 and a plate 194 which is moved along theguide plate against a force of a spring 193 by actuating a solenoid 192.The plate 194 has formed therein, an aperture 196 for standardphotometric measurement, and an aperture 197 for passing the scatteredand/or fluorescent light therethrough.

In case of effecting the nephelometric and/or fluorometric analyses byutilizing the scattering and/or fluorescent light from the test liquid,it is preferable to form the bottom portion 45c of the cuvette 45 as aflat surface 45e instead of a semicylindrical bottom surface asillustrated in FIG. 44. In this manner, it is possible to furtherincrease the utility of the current invention by providing foradditional measurement techniques, i.e. nephelometryc and/orfluorometry.

In the above embodiment for the nephelometric and fluorometric analyses,use is made of the light-receiving element separated from that ofstandard photometry, but a single light-receiving element may becommonly used for the transmitted, scattered and fluorescent light.FIGS. 45 to 48 show several embodiments of such capability. In FIG. 45,a cuvette 45' is so arranged that incident light impinges verticallyupon a transparent incident surface and the light passing through thecuvette and the test liquid contained therein is received by an element200 so as to effect the photometric measurement as shown in FIG. 45A.Then, the cuvette 45' is slightly rotated as shown in FIG. 45B, so thatthe transmitted light deviates from the optical axis of the element 200and thus, the scattered light and/or the fluorescent light impinges uponthe element 200. In this manner, the nephelometric and/or fluorometricanalyses can be carried out. In FIGS. 46 and 47, the light-receivingelements 201 and 202 are so arranged that they can receive the scatteredand/or fluoroscent light, and transmitted light is directed to theelement via a rotating mirrors 203 and 204. In FIG. 46, the scatteredand/or fluorescent light from a side wall of the cuvette 45' impinges onthe element 201 through a scattering element 205. In FIG. 47, thescattered and/or fluorescent light from the bottom of the cuvette 45'impinges on the element 202. When performing standard photometricanalysis, the rotating mirrors 203 and 204 are positioned as shown inthe drawings and the transmitted light is recieved by the elements 201and 202. During the nephelometric and/or fluorometric analyses, themirrors 203 and 204 are rotated to a position shown by center lines andonly the scattered and/or fluorescent light impinges upon the elements201 and 202. In an embodiment shown in FIG. 48, the cuvette is so shapedthat conventional photometric, nephelometric, and fluorometric analysescan be effected by a common light-receiving element 206. As shown inFIG. 48A, when performing conventional photometric measurements, use ismade of a cuvette 45' having transparent walls perpendicular to theincident light, whereas when performing nephelometric and/orfluorometric analyses as shown in FIG. 48B, use is made of a cuvette 45"having a transparent wall inclined to the incident light.

As explained above, by effecting conventional photometric, nephelometricand/or fluorometric analyses by means of a common light-receivingelement, the construction of the photometer can be much simpler.

Further in the embodiment explained above the wavelengths for particulartest items are selected by the rotary filter unit 53 shown in FIGS. 7and 8. Alternatively the optical fibers for transmitting light passingthrough the test liquid to the photodetector may have desired differenttransmission wavelengths and a given one of which may be selectivelyinserted in the optical path for receiving the light in dependence uponthe test item to be analyzed.

What is claimed is:
 1. A reaction vessel for use in a chemical analyzingapparatus comprising:a bottom portion including a curved wall defining asemi-cylinder, said curved wall having first and second side edgessubstantially parallel to a longitudinal axis of said semi-cylinder andfirst and second end edges substantially perpendicular to saidlongitudinal axis, said bottom portion further including transparentsemi-circular end windows adjoining said curved wall at said first andsecond end edges, said end windows being substantially perpendicular tosaid longitudinal axis of said semi-cylinder; an upper portion includingside walls adjoining and tapering outwardly from said first and secondside edges and said end windows of said bottom portion, said side wallsforming boundaries of a rectangular opening at an end of said upperportion opposite from said bottom portion; and a flange attached to eachof said side walls at the end of the said upper portion opposite fromsaid bottom portion and extending outwardly from said side walls, saidflange being substantially coplanar with said rectangular opening.
 2. Areaction vessel according to claim 1, wherein said reaction vessel isformed as a molded body of transparent material.
 3. A reaction vesselfor use in a chemical analyzing apparatus comprising:a molded body oftransparent material configured to define a reaction vessel such thatsaid reaction vessel includes: a semi-cylindrical bottom portion havingupright semi-circular end windows defining ends of said semi-cylindricalbottom portion along a longitudinal axis of said semi-cylindrical bottomportion, and through which photometry may be effected, a top of saidsemi-cylindrical bottom portion forming the periphery of a firstsubstantially rectangular opening; a plurality of tapered side wallsattached to said semi-cylindrical bottom portion and with each one ofsaid plurality of side walls extending from a corresponding edge of saidfirst substantially rectangular opening and widening outward toward asecond substantially rectangular opening; and a flange attached to eachone of said plurality of side walls and extending outwardly from theperiphery of said second substantially rectangular opening.
 4. Areaction vessel for use in a chemical analyzing apparatus consistingof:a molded body of light transparent material defining a reactionvessel and consisting of: a semi-cylindrical bottom portion havingopposite ends terminating in upright semi-circular end windows definingan axis along which light may be transmitted to effect photometry, thetop edges of said semi-cylindrical bottom portion forming a firstrectangular opening; side walls coupled to said bottom portion at saidedges defining said first rectangular opening and outwardly taperedtherefrom to widen said first rectangular opening toward a secondrectangular opening; and a flange coupled to said side walls andextending about said second rectangular opening.